In recent years, ID chips such as RFID (Radio Frequency Identification), Ubiquitous ID and μ-chip have been developed. The greatest feature of these chips is a capability of communication with an ID reader in a non-contact manner. A part of such products has been already practically used as a chip embedded in a card such as a commuter pass. These non-contact ID chips having advantages of compact size, availability without power-source, and unbreakability, are expected to be popularized with improvement in cost reduction.
Many techniques utilizing such non-contact ID chips have been proposed.
For example, Japanese Patent Application Laid-Open No. 2001-116583 discloses a technique for grasping the position of an ID inside a room by placing an ID reader in two sides of the room.
Japanese Patent Application Laid-Open No. 2001-350485 proposes a technique for notifying a user of information retrieved from a detected ID.
Further, Japanese Patent Application Laid-Open No. 2000-188640 proposes an in-the-home health care administration system to examine a user's auditory difficulties from the user's non-contact ID and change speech characteristic to be outputted in correspondence with the auditory difficulties.
Further, Japanese Patent Application Laid-Open No. 2002-215012 proposes a learning assistance apparatus utilizing non-contact ID.
As described above, many proposals have been made to cause/change an action in accordance with a detected non-contact ID. However, there is no proposal for determination of action upon detection of plural non-contact IDs.